Wideband Ferrite Chip Common-mode Filter
For The Next-generation Digital Interface HDMI,
ACM2012H-900
Conforming to RoHS Directive
Conformity to RoHS Directive: This means that, in conformity with EU Directive 2002/95/EC, lead,
cadmium, mercury, hexavalent chromium, and specific bromine-based flame retardants, PBB
and PBDE, have not been used, except for exempted applications.
HDMI, the next-generation digital interface, allows high-speed transmission of high-resolution video signals
and multi-channel audio signals without compressing them. As the first EMC component manufacturer to
be registered as an Adopter, TDK has been cooperating with the makers of IC chips, devices, and connec-
tors in the development of ideal common-mode filters for HDMI.
ACM2012H-900 is the latest achievement of the effort. While accurately reducing
radiation noise, a superb frequency characteristic for transmission of HDMI's qual-
ity and speedy differential signals without any distortions is realized.
Shapes and dimensions / Equivalent circuit
2.0 0.2
1.2 0.2
Impedance vs. frequency characteristics
1000
1.2 0.1
Impedance (Ohm)
0.4
0.35 0.5 0.35
1.2
0.4
Dimensions in mm
0.8
100
Common mode
10
Differential mode
0.05
Recommende
PC board pattern
(Reflow process)
0.35
1
1
10
100
Frequency (MHz)
1000
10000
0.5
Operating temperature range
-
25
to +85
°
C
Nondirectional
0.75
1.2
Dimensions in mm
Recommended soldering conditions
Lead-free solder/High-temperature reflow process
245
°C
Typical Electrical Characteristics
Common-mode Impedance
DC resistance Rdc
Rated current Idc
Rated voltage Edc
Insulation resistance
Cutoff frequency
Characteristic impedance
(ohm)
(ohm)
(mA)
(V)
(ohm)
(GHz)
(ohm)
65 min/90 typ. [at 100MHz]
0.30 max. [1-line]
300 max.
20 max.
20M max.
6 typ.
100 typ.
230
°C
Slow
cooling
10 to 30 s
180
°C
150
°C
Preheating : 60 to 120 s
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ACM2012H
1
Three rigorous requirements for
the common-mode filter for HDMI interface
HDMI's maximum data transmission speed can be as
fast as 1.49Gbps. When applying a common-mode
filter as an EMC countermeasure for this rapid inter-
face, the insertion loss characteristic (Sdd21) is the
first thing to be considered.
For instance, the cutoff frequency ( insertion loss:
-3dB) of ACM2012-900, which is optimized for USB2.0
of 480Mbps transmission speed, is 1.6GHz, although
it has to be increased to 6GHz in order to achieve a
good reduction effect against radiation noise with-
out breaking HDMI's transmission waveforms.
The characteristic impedance when installed on a
transmission line is also vital to consider. The stand-
ard value (TDR Standard) of HDMI is 100 ohms plus or
minus 15 ohms. Being rapid means stricter (narrower)
requirements than those of USB2.0.
The eye-pattern standard verifies the transmission
waveform per se - a comprehensive determination
test of "aptitude" for the HDMI interface. The test is
considered passed if there is almost no difference
between the waveforms before and after the inser-
tion, but considered not applicable if the eye pat-
tern crosses the transmission waveform even a little.
ACM2012H-900
INFORMATION
HDMI, based on the DVI standard used for PC displays,
is a new digital interface with additional features for the
next-generation of audio visual devices in which back-
ward compatibility is maintained.
The connectors and cables are made slimmer and
smaller by reducing the number of TMDS links and re-
moving analogue RGB from the specification for cost
saving and simplified inter-device connection. HDMI
allows the sending and receiving of digital audio as
well as digital image through one interface cable.
Being digital means less degradation of the signal com-
pared to the analogue D interface. The YCrCb con-
nection, used frequently for many audio visual home
appliances, in addition to RGB, is also supported. Cur-
rently, use of HDMI in digital TVs, harddisk TVs, DVD play-
ers, projectors, and so forth, has been becoming in
creasingly popular.
The website of HDMI
http://www. hdmi.org/
High Definition Multimedia Interface and HDMI are trademarks of HDMI Licensing, LLC.
Feature -1
The cutoff frequency was boosted to 6GHz
6GHz
Insertion loss frequency characteristics
(Sdd21)
0
1
2
3
Insertion loss (dB)
4
5
ACM2012H-900
The cutoff frequency (3dB insertion loss)
was raised to 6GHz. Therefore, high-speed
HDTV signals can be transmitted without
distortion.
Unprecedented high efficiency will be offered for
other high-speed differential transmission interfaces.
USB2.0-ready products:ACM2012-900
6
7
8
9
10
1
10
100
Frequency (MHz)
1000
10000
It is applicable on both Tx and Rx sides of diverse
audio visual devices with the HDMI interface, such
as Set-top boxes, DVD recorders, digital TVs/hard
disk TVs, LCD projectors, and so on.
It will provide the optimal effect for the EMI counter-
measure against high-speed differential signal inter-
faces such as USB2.0, IEEE1394 and Serial-ATA , not
to mention the DVI interface for PCs
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ACM2012H
2
Feature -3
Fully compliant with
HDMI's eye-pattern standard
As shown in the measurement result below, it com-
plies with the eye-pattern standard of HDMI with an
ideal transmission waveform.
ACM2012H-900
Eye pattern of the data signal
Comparison of before/after countermeasures
Initial condition
(Through)
HDMI-ready
ACM2012H-900 is integrated
Test-1
ACM2012H-900 is integrated
in each line on the Tx side.
Referential example
ACM2012-900 is integrated
in each line on the Tx side.
200mV/div 200ps/div
200mV/div 200ps/div
Test-2
ACM2012H-900 is integrated
in each line on the Tx and Rx sides.
With almost
no waveform
distortion,
transmission
waveform
quality that's
almost equal
to the initial
condition is
maintained.
Referential example
ACM2012-900 is integrated
in each line on the Tx and Rx sides.
200mV/div 200ps/div
200mV/div 200ps/div
Measurement system
Type A Plug
Type A Receptacle
CLOCK
DATA 0
DATA 1
DATA 2
Referential example
USB2.0-ready
ACM2012-900 is integrated
Test Board-Tx
HDMI
Transceiver
IC
Common-mode Filters
HDMI Cable (2m)
Tektronix
TDS6604
CH.1 CH.2
P7330(3.5GHz)
Differential probe
200mV/div 200ps/div
ACM2012H-900
CLOCK
DATA 0
DATA 1
DATA 2
P6249(4GHz)
FET probe
Test Board-Rx
HDMI
Receiver
IC
Trigger
Test point
Recovery
clock
(Clock x 2.5)
200mV/div 200ps/div
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ACM2012H
4
Feature -4
Superb reduction effect against
radiation noise
Using the 3m-test method, electric field strength
radiated from the system which transmits an HDMI
signal of 742.5Mbps was measured.
ACM2012H-900
Example of radiation noise
reduction effect
Measuring standard: The 3m-test method is used.
Initial condition
ACM2012H-900 is integrated in each line on the Tx side.
Horizontal polarization
100
Radiation electric field strength (dB V/m)
Vertical polarization
100
Radiation electric field strength (dB V/m)
80
80
60
60
40
FCC ClassA
FCC ClassB
40
FCC ClassA
FCC ClassB
20
20
0
10
100
1000
Frequency (MHz)
10000
0
10
100
1000
Frequency (MHz)
10000
In measuring the result before the countermeasure,
a few higher harmonic peaks were observed
around the fundamental wave, and GHz bands had
been beyond the required level of FCC Class B.
But after the countermeasure, all peaks were reduced
to within an acceptable level.
Measurement system
ACM2012H-900
CLOCK
DATA 0
DATA 1
DATA 2
Test Board-Tx
Graphic
Data
HDMI
Transceiver
IC
Test Board-Rx
HDMI
Receiver
IC
HDMI Cable
(1m)
SHIELD
SHIELD
BSF-B07EA 2005.10
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ACM2012H
5
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